Connector assemblies for hollow members

ABSTRACT

A connector assembly for fixed angular attachment of two hollow elements such as tubes or to another element such as a frame comprises two pressure members pivotally connected intermediate their ends for relative movement about a transverse axis and adapted for axial introduction together into said hollow element, one of the members having a large area pressure surface for slidable and bearing engagement with one internal surface of the associated hollow element while the other member is adapted to engage an opposite internal surface of the associated hollow member, the other of the members being so constructed and arranged as to be energized by lateral pressure during axial introduction in to the hollow element for providing means resiliently biasing said members into engagement under pressure with opposite internal surfaces of said hollow element. The energization may be effected by shaping the other member as a resilient beam, or by providing resilient bodies between the members.

iUnite States atet [191 [111 3,829,226 lfireusel 1 Aug. 13, 1974 CONNECTOR ASSEMBLIES FOR HOLLOW MEMBERS Filed: Apr. 13, 1972 Appl. No.: 243,623

[76] Inventor:

[30] Foreign Application Priority Data Apr. 13, 1971 Austria 3116/71 U.S. Cl 403/295, 52/585, 52/656, 52/758 H, 403/297 Int. Cl. F16lb 7/00 Field of Search 287/2, 54 C, 124, 20.92 D, 287/20.92 Y, 189.36 11,52/585, 656, 758 H; 403/295, 297

[5 6] References Cited UNITED STATES PATENTS FOREIGN PATENTS OR APPLICATIONS 355,731 8/1931 Great Britain 287/54 C Primary Examiner-Mervin Stein Assistant Examiner-David H. Corbin Attorney, Agent, or FirmStrauch, Nolan, Neale, Nies & Kurz 5 7] ABSTRACT A connector assembly for fixed angular attachment of two hollow elements such as tubes or to another element such as a frame comprises two pressure members pivotally connected intermediate their ends for relative movement about a transverse axis and adapted for axial introduction together into said hollow element, one of the members having a large area pressure surface for slidable and bearing engagement with one internal surface of the associated hollow element while the other member is adapted to engage an opposite internal surface of the associated hollow member, the other of the members being so constructed and arranged as to be energized by lateral pressure during axial introduction in to the hollow element for providing means resiliently biasing said members into engagement under pressure with opposite internal surfaces of said hollow element. The energization may be effected by shaping the other member as a resilient beam, or by providing; resilient bodies between the members.

17 Claims, 8 Drawing Figures PATENIEU AUB1 3 1974 SHEET 1. OF 4 PATENTEU w 1 3 m4 3.829.226

SHEU 3 I]? 4 I PAIENIED nun] 31974 SHEH W BF 4 CONNECTQR ASSEMBLHES FOR HULLOW MEMBERS The invention relates to connector assemblies for the corner or butt end connection of at least one hollow eement such as a tube with an additional frame element which may be another tube, for example which may be another tube for the construction of window or door frames or a railing, etc., wherein the connector assembly is provided with at least one pair of spreadable members to be inserted into the hollow element, the members having surfaces engaging the opposite inside surfaces of the hollow element under pressure.

Arrangements for corner connections have been pro- A further important object of the invention consists in that a connecting arrangement is provided wherein a pressure member is formed with a pressure surface which, in the direction of insertion of the pressure member into the hollow element, has projecting terminal areas and a relatively depressed or sunken middle area whereby the pressure member is elastically resilient between the projecting terminal areas, so that the effective plane of the pressure surface and in the case of a pressure load of the pressure member will adjust itself to the height between that of the projecting termi nal areas and that of the sunken middle areas. At the same time the pressure member can carry at least on one of the terminal areas of its pressure surface a proposed which have flanges extending into the opening of lecting Clamping element made of elastically resilient the hollow element, the flanges being pressed by wedges against the two opposite walls of the hollow element.

These arrangements for corner sections are disadvantageous because shifting of the wedges along the elements make it necessary to provide openings which subsequently must again be closed; Moreover, in the case of every wedge connection, insofar as it is not additionally secured, a gradual loosening by shocks is unavoidable. Furthermore, arrangements for corner connections have been known which consist essentially of an angular member inserted into the opening of the hollow element. on each side of such angular elements there are resilient parts, such as leaf springs or elastic lamellae, which press against the inside surfaces of the hollow element. No firm and precisely fitting connection can be achieved with these angular members.

In comparison one main object of the invention is that a connection assembly is to be created, which is distinguished during assembly by very simple handling and by time saving and which does not require any additional processing of the material of the hollow element. Moreover, the connector assembly is such that it will be able to compensate for differing inside widths of certain hollow elements. Also, the connector assembly is capable of being produced in as few basic sizes as possible and nevertheless being usable in the pertinent size in a largerange of hollow element sizes.

A further object of the invention is to provide a novel connector assembly for attaching a hollow element such as a tube to another member, wherein a pressure member is pivoted on a counterpressure member and the two members axially slide within the hollow ele ment while being resiliently biased against opposite inner walls of the hollow element.

This object may be achieved according to the invention by providing pressure members in the form of twoarmed levers connected with one another via a toggle lever joint and disposed at a distance from one another, whereby at least one pressure member of each pair is provided with elastic clamping arrangements for compensating for tolerances in the inside dimensions of the hollow elements. The connector assembly vof the invention can be produced cheaply and can be inserted in a simple manner quickly and securely into hollow elements. When inserting a connector assembly according to the invention in hollow elements, large surface areas of the pressure members fit against opposite inside surfaces of the hollow elements and distribute the pressure there with minimum danger of deformation or even destruction of the walls of the hollow elements.

material, for example, a synthetic substance or rubber.

Another important object of the invention consists in providing a connecting arrangement of the foregoing type in which at least one of the pressure members has a pressure surface which, in the direction of insertion of the pressure member into the hollow element, has projecting terminal areas and a sunken middle area and in this case the pressure member can be plastically deformed in at least one of these projecting terminal areas, as a result of the pressure exerted upon it during insertion, so that the effective plane of the pressure surface will adjust itself to the height between that of the projecting terminal areas and that of the sunken middle area in the case of a compressive: load of the pressure member.

Another object of the invention consists in providing a connecting arrangement of the foregoing type in which at least one of the pressure members is formed with a pressure surface, which, in the direction of insertion of the pressure member into the hollow element, has a rear projecting terminal area and a sunken middle area, and in which an elastically compressible supporting element has been attached to the inside surface of said pressure member facing away from the pressure surface, which element is supported by the second pressure member so that the effective plane of the pressure surface in the case of compressive load of the pres sure member adjusts itself to the height between that of the projecting rear terminal area and the sunken middle area while tilting the pressure member on the toggle lever joint with compression of the supporting element.

Another object of the invention is the creation of a connecting arrangement of the foregoing type in which at least one of the pressure members is formed on its compression surface with toothed areas or sharp edged formations for engaging the inside surface of the hollow element, which provide space between the inside surface of the hollow element and the pressure member in order to allow air to pass through and to make possible circulation of the air in a frame, etc., constructed of hollow elements, for disposal of moisture.

A further important object of the invention is the cre ation of a connecting arrangement of the foregoing type in which one of the pressure members of the pair of pressure members on its inside facing the second pressure member has a bearing groove located at a perpendicular distance from the effective plane of its pressure surface in order to form the toggle lever joint, while the second pressure member on its inside surface facing the first pressure member has joint support with groove preferably may have a semicircular cross section and the joint head should have a three-quarter circular cross section fitting in said semicircular cross section.

Another object of the invention consists in providing a distancing element in a connector assembly of the foregoing type, which is to be placed solidly and nonrockably on the joint support in order to extend that support whereby the distancing element at its free end is developed for the flexible engagement with the joint groove of the other pressure member for the formation of an extended toggle lever joint. As a result of this distancing element, it will be possible to adapt the connector assembly to hollow elements having different widths, in which the same pressure members are used but in which a wider or narrower distancing element is inserted depending on the width of the hollow element. Therefore, for correlating the connector assembly with various hollow elements, one needs only different distancing elements, which however merely represent small additional elements as compared to the pressure members.

Furthermore,it also is an object of the invention to provide a connector assembly of the foregoing type in which one of the pressure members of the pair of pressure members is formed with a substantially flat pressure surface and is solidly connected with arrangements to form one unit for attachment to at least one other frame element. In this way the elements assembled by means of the connecting arrangement according to the invention fit in a very precisely predetermined position relative to one another.

Finally, it also is an object of the invention to create a connecting arrangement of the foregoing type for connection of two or more hollow elements in which two or more pairs of pressure members are provided, whereby each pair of pressure members contains a first movable pressure member and a second relatively fixed pressure member and whereby each of these second pressure members are formed with an essentially flat pressure surface and all are solidly connected to form a unit in the shape of an angle, crosswise or a star, whereby the essentially flat pressure surfaces constitute with one another a slightly larger angle than the desired angle between the assembled angular section elements. At the same time for example the angle located between the flatly developed pressure surfaces of one unit of pressure bodies for formation of a rectangular connection of, two section elements can amount to about 91.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevation partly in section showing a connector assembly for angularly disposed hollow elements, according to an embodiment of the invention;

FIG. 2 is a side elevation partly in section similar to FIG. 1 but including a modified connector assembly;

FIG. 3 is a side elevation partly in section similar to FIG. 1 but showing another embodiment of the connector assembly;

FIG. 4 is a side elevation showing a connector assembly somewhat like that of FIG. 2 but including a spacer inserted between the pressure members;

FIG. 5 is a side elevation showing a modified pressure member that may be used in the connector assemblies of FIG. 2 or FIG. 4;

FIG. 6 is a side elevation showing a connector assembly consisting of a star shaped unit having three fixed pressure members;

FIG. 7 is a side elevation showing a connector assembly consisting of a cross shaped unit having relatively fixed pressure members; and

FIG. 8 is a side elevation partly in section showing a connector assembly according to another embodiment of the invention for the butt end connection of two members at least one of which is hollow.

FIGS. 1-3 illustrate the corner connection of two similar size hollow elements shown as square crosssection tubes 10.

Referring to FIG. I the connector assembly comprises two pivoted pressure members lll and two rigidly interconnected counterpressure members 12 providing a counterpressure unit. As shown, counterpressure members 12 are integrally joined to extend at a fixed angle with respect to each other, and each of pressure members 11 is pivotally or swivelly mounted on a counter-pressure member.

In FIG. 1, two tubes 10 are connected together as in FIGS. 2 and 3, the upper tube 10 being indicated only in outline in FIG. 1. The connector assembly is so disposed that one counter-pressure member 12 slidably engages the inner surface of one tube, while the other member 12 similarly has slidable engagement with the inner surface of the other tube. Thus in FIG. 1 the counter-pressure unit has flat pressure surfaces 15 in slidable flush contact with inner surfaces of the tubes to be joined at the inner corner of the junction.

Each counterpressure member 12 is formed near its free end with a bearing socket 13, preferably in the form of a transverse cylindrical groove. This groove is preferably located in the last quarter of length of the member 12.

Each pressure member 11 is formed opposite and facing a groove 13 with a joint support 16 having a beaded joint element 17 having a bearing fit within groove 13, so that the respective pressure members are pivoted to the counterpressure members near their ends which are remote from the juncture of the tubes 10. In the illustrated embodiment, joint element 17 is formed with a three quarters circular surface whereby the joint provides a substantially swivelled connection between each pressure member and a counterpressure member.

The central axis of joint element 17, which lies on the transverse axis of cylindrical groove 13, is spaced a predetermined linear distance, indicated at 14, with respect to pressure surface 15. Similarly this axis is located a predetermined linear distance, indicated at 18, with respect to the effective contact surface indicated at 19. This effective contact surface 19 would be determined by the projecting part of pressure plate 11, and it lies in this embodiment in each instance in the planes of the wall surfaces of tube 10 opposite the wall surfaces engaged by the counter-pressure unit.

Each pressure member 11 carries near its free end and outwardly beyond the pivot region an elastic clamping element 20 in the form of a strip of rubber,

plastic or any elastomer extending transversely of the outer surface 21 of pressure member II. As shown in FIG. I, each surface 21 is depressed between clamping element 2% and a transversely corrugated outer region 22 at the opposite end from clamping element 20 facing the adjacent tube wall.

Each pressure member 11 is formed on the opposite side from the corrugated region with a transverse groove 23 mounting an inserted elastic support pad 24 adapted to resiliently engage the adjacent counterpressure member 12.

Through the distance 14 of the middle axis of bearing groove 13 from pressure surface 15 of counterpressure member I2 and as a result of the distance 118 of the middle axis of joint element 17 from the effective contact surface 19 of pressure member 11, this effective joint between pressure member 11 and counterpressure member 112 constitutes a toggle lever joint. In addition, pressure members 11 and counterpressure member 12 constitute two-armed levers with regard to the joint constituted by the bearing groove and headed joint element I7, by the swivelling of which levers the toggle lever joint becomes effective for production of a high contact pressure of pressure member I1 and counterpressure members 112 against the inside surfaces of the hollow tubes.

FIG. I shows the connector assembly of the invention at the stage where one counterpressure member thereof has been axially inserted into one hollow element 10. Pressure member 11 upon insertion into tube as shown at the left in FIG. I has its clamping element 20 pressed against the inside surface of hollow tube It] and at the same time pressure surface of the associated counter-pressure member ll2 also presses firmly against the inside surface of the opposite wall of tube 10. Clamping member and counter-pressure member 12 thus slide upon the opposed inner surfaces of tube 10 during such insertion. As the projecting corrugated region 22 enters tube 110, it engages and slides along the surface of tube It), and pressure member pivots upon its axis at I7 to swing the trailing end of the pressure member toward counterpressure member I2. The resilient support pad 24 engaging member 12 opposes this swivelling, whereby the corrugations at 22 are resiliently continuously urged against the inside surface of the tube 10. In this manner a solid tight connection is created.

In the embodiment of FIG. I, the two counterpressure members 12 are rigidly connected with one another in a one-piece angular unit and between their pressure surfaces 15 they constitute an angle beta, which in the example shown amounts to 91. Experience has shown that this angle of 9ldue to the deformation occuring with the forcing-in of the structural connection arrangement and especially because of forced expansion at the end of hollow tube 10 results altogether, i.e., across the entire length of the assembled hollow elements 110, in an angle of 90 for the joint between tubes 110. The precise formation of the connecting angle also is achieved by the two pressure members llll being located on the outer sides of the angle while the adjacent pressure surfaces 15 of counterpressure members 12 guarantee the precise dimensional stability of the connecting angle. 7

In FIG. I a second tube 10 having an angle cut end is slipped endwise over the free leg into end abutment b with the other tube MI in the position shown best in FIGS. 2 and 3.

In the embodiment of FIG. 2, a somewhat simplified connector assembly is shown. In this form the bearing groove 13 is formed on a pressure member 11, while the counterpressure member 12 carries joint support 16 and joint element I7 which have same shape and fit with cylindrical groove 13 as in FIG. I. The swivel axis, here indicated at 25, lies at such relative distances to the pressure surface 15 of counterpressure member 12 and to the effective plane of pressure surface 21 of pressure member II that a toggle lever joint is formed as in FIG. 1. For providing an effective clamping arrangement, pressure member Ill in this embodiment tapers from its center toward its ends and is elastic to provide a resilient beam. Member II is thus depressed in the middle area opposite the projecting end areas 26 and 27 that engage the inside surface of tube 110. In this manner each pressure member 11 deforms elastically during insertion of the connector assembly into the hollow elements 10, in such a way that the active contact surface which in FIG. 2 coincides with inside surfaces of hollow tubes It) approaches the sunken area of pressure surface 21 of pressure plate II. In this manner a continuous clamping pressure is exerted by pressure plate 11 at the two end areas 26 and 27 on the inside surface of the adjacent hollow tube 10. In FIG. 2 it will be noted that the counterpressure unit consisting of integrally joined members 12 has its pressure surfaces 15 engaging the inner wall of one tube 10 and the outer wall of the other tube, and the pressure members II are correspondingly associated with the tube inner surfaces.

In the embodiment of FIG. 3, the connector assembly is essentially the same as in FIG. 2, the difference being that additionally a resilient support buffer 28 is disposed between each counterpressure member 12 and the end of the associated member II that last enters a tube If) during insertion. In FIG. 3 these buffers 28 are disposed near the juncture of tubes 10. Each support buffer 28 is mounted in a transverse groove in counterpressure member I2. Upon introduction of associated pressure and counter-pressure members into a hollow tube It), pressure member I1 is not only elastically deformed as in FIG. 2 but it is rocked about its pivot so that the clamping action of pressure member Ill on the inside surface of hollow tube It) is increased. Especially, it is possible in this manner to exert a sufficient clamping action even where there are relatively large tolerances in the inside dimensions of tubes 10.

FIG. 4 shows a modified connector assembly wherein pressure member Ill and counterpressure member 12 are constructed similarly to FIG. 2, except that a spacer 29 is inserted between the pressure and counterpressure members. This spacer 29 is formed at its underside with a transverse groove 30 which in cross section corresponds to the cross section of joint support 16 and beaded joint element 17 of the counterpressure member 12. At opposite sides of receiving groove 30, spacer 29 is formed with support surfaces 31 engaged by counterpressure plate 12, so that the spacer does not rock with respect to member 12. On the opposite side, spacer 29 carries a joint support 32 with a beaded joint element 33 which correspond in cross section to joint support 16 and beaded joint element 17 of counterpressure member ll2 and likewise fits into a bearing groove 13 of pressure member Ill.

The spacer 29 can be of variable height, so that by selection of the proper spacer 29 the connecting arrangement can be adapted practically to any width or diameter of hollow element 10. It is also possible to provide a connector assembly wherein the counterpressure unit has mounted on one member 12 a directly pivoted member Ill as in FIG. 2 and on the other member 12 a spaced pivoted unit as in FIG. 4 for different combinations of tubes 10.

FIG. 5 shows a modified form of pressure member 11 in which pressure surface 21 has been provided with transverse ridges or spacers 34. These spacers serve the purpose of forming air permeable spaces between the effective pressure member surface 21 and the opposite inner surface of hollow element in order to allow moisture which may be present in the hollow element to evaporate. In FIG. 5, the spacers 34 are developed as a sawtooth corrugation with the corrugations parallel. However it also is possible to provide different form spacers such as nubs and the like. In order to obtain the depression of pressure surface 21 in its central area, the points of the spacers 34 lie in two planes which intersect at the central area at a convex angle of about 185.

The spacers 34 of pressure member 11 in FIG. 5 may be of the same material, for example, aluminum, which can be permanently i.e., plastically, deformed. Upon insertion into a hollow element It), the spacers 34 disposed in the terminal areas of pressure surface 21 then are compressed with plastic deformation so that the effective plane of pressure surface 21 will adjust itself at a height lying between that of the original height of spacers 34 and that of the sunken middle part of pressure surface 21.

Connector assemblies of the invention are not limited to the angular connection of two hollow elements 10.

FIG. 6 shows an arrangement for a star shaped connection of three hollow elements. For this purpose three counterpressure members 12 of substantially the same structure as those according to FIG. 1 are rigidly connected with one another to form one unit, in the form of a star, as at an angle gamma 120. Three pressure members 11 essentially of the same structure as those of FIG. 1 (not shown) would be pivoted on counterpressure members 12 in the same manner as in FIG. I.

In FIG. 7, four counterpressure members 12 are joined integrally to form a one-piece cross. These counterpressure members 12 are of the same structure as in FIG. 1, and each is provided with a bearing groove 13 for pivotally mounting the pressure members 11 as in FIG. 1. Corresponding parts are correspondingly numbered. Adjacent counterpressure members 12 are disposed with pressure surfaces 15 facing each other, whereby these pressure surfaces 15 facing each other in pairs enclose an angle beta which, as in FIG. 1, is somewhat larger than 90 and can amount for example to 91.

The counterpressure surfaces 15 of oppositely extending counterpressure members 12 in the cross in FIG. 7 lie at a mutual distance 35 which corresponds substantially and is equal to the inside width of the ho]- low element 10, which is to be combined therewith. As a result, a noticeable displacement of the hollow elements 10 opposite each other in the cross will be avoided. As a reinforcement, connecting and reinforcing elements 36 have been developed in the center of the cross shaped unit of counterpressure members, which elements constitute shoulders 37. At a small distance from these shoulders, the associated pressure members ll'terminate so that these members in FIG. 7 are somewhat shorter than in FIG. 1.

In the embodiment of FIG. 8, the connector assembly according to the invention is provided for butt end connection of a hollow element 10' with some other frame element 40, which, for example, also can be a hollow element. Frame element 40 has outside projections 41 and 42. In FIG. 8, the counterpressure member 12' has been developed at one end as a clamping support 38, into which the projections 41, 42 of frame element 40 fit. In this example, the counterpressure plate I2 is formed only for association with a single pressure member 11 and in addition, and analogously to the embodiment according to FIG. 2, it has a pressure surface 15 and a joint support 16 which carries a beaded joint element 17 at its free end journaled in a transverse groove 13 in pressure member 11. Pressure member 11, which is to be mounted on the counterpressure member is similar to that of FIG. 2 or that of FIG. 5.

For using a connector assembly according to FIG. 8, the counterpressure member 12 at first is fastened to the frame element 40 and then the hollow element 10 is slipped over the pressure surfaces 15 and 21 of counterpressure member 12 and pressure member 11 until it abuts against frame element 40. The end of tube 10 may be suitably cut to interfit with frame element 40. As a result of the combined pressure and clamping action of the connector assembly, the hollow element 10 is attached to frame 40 and in addition the projections 41 and 42 of frame 40 are wedged in the recesses 39 of clamping support 38, so that a movement of the counterpressure member 12' along frame element 40 no longer takes place normally. However, if desired, a further safeguard can be created by wedging projections 41 and 42 of frame element 40 additionally in recesses 39 of clamping support 38 prior to slipping on the hollow section element 10.

It will be observed that in all embodiments of the invention the counterpressure member 12 (12) has a large area pressure surface consisting of a major portion of its side area in flush slidable and bearing contact with the adjacent inner surface of a hollow element. This distributes the holding forces and helps prevent deformation of the tube walls.

I claim:

1. A connector assembly for fixed attachment of a hollow element such as a tube to another element, said assembly consisting essentially of two pressure members rockably engaged intermediate their ends, and adapted for axial introduction together into said hollow element, one of said members having a large area pressure surface formed for frictional engagement with one internal surface of said hollow element while the other of said members is adapted to engage an opposite internal surface of said hollow element, the other of said members being so constructed and arranged as to be energized solely by lateral pressure during said axial introduction into the hollow element between said internal surfaces for providing means resiliently oppositely biasing said members into engagement under pressure with the opposite internal surfaces of said hollow element, said one pressure member being a rigid body having a relatively large surface area for frictional engagement with said one internal surface of the hollow element, and said other pressure member comprising a lever separate from said body having intermediate its ends bearing surface means in rockable contact with bearing surface means on said one pressure member for rocking transversely of said hollow member, the effective axis of rocking being substantially normal to the direction of introduction of said assembly into the hollow element, said lever being adapted to bear at opposite ends only on said opposite internal surface of the hollow element.

2. A connector assembly for fixed attachment of a hollow element such as a tube to another element, said assembly comprising two pressure members rockably engaged intermediate their ends and adapted for axial introduction together into said hollow element, one of said members having a pressure surface formed for slidable engagement with one internal surface of said hollow element while the other of said members is adapted to engage an opposite internal surface of said hollow member, the other of said members being so constructed and arranged as to be energized by lateral pressure during said axial introduction into the hollow element for providing means resiliently biasing said members into engagement under pressure with opposite internal surfaces of said hollow element, said one pressure member being a rigid body having a relatively large surface area for contact with said one internal surface of the hollow element, and said other pressure member comprising a lever separate from said body, means forming coacting engaged bearing surfaces on said lever and body providing for rocking of said lever relative to said body and transversely of each hollow member during introduction of said assembly into the hollow element, said lever being adapted to bear only at opposite ends on said opposite internal surface of the hollow element, and resilient means provided between said lever and the one pressure member substantially opposite the region where one end of said lever is adapted to bear on the opposite internal surface of said hollow element.

3. A connector assembly for fixed attachment of a hollow element such as a tube to another'element, said assembly comprising a first pressure member in the form of a rigid body having a relatively large surface area adapted to engage one internal surface of said hollow element, a second pressure member in the form of a lever separate from said body, bearing surface means on said lever intermediate its ends having coacting engagement with bearing surface means on said body providing said lever with a free pivotal connection with said first pressure member for rocking about an axis normal to the direction of introduction of said assembly into said hollow element, said lever being adapted to engage an opposite internal surface of said hollow member only at opposite ends, projecting means at said opposite ends of the lever adapted to positively engage said opposite internal surface of said hollow element, said rocking axis being disposed between said two pressure members at a first predetermined distance from said surface area of said first pressure member and at a second predetermined distance from a plane containing the surface of engagement between said projecting means of said lever and said opposite internal surface of said hollow element when the assembly has been fully introduced into said hollow element, and said surface area of said first pressure member and said plane being disposed at such predetermined distance from each other as to cooperate in pressing said surface area of said first pressure member against said one internal surface of said hollow element and said projecting means of said lever against said opposite internal surface of said hollow element when said assembly has been fully introduced into said hollow element, and said assembly comprising resilient means acting to urge said lever against said opposite internal surface of said hollow element when said assembly has been fully introduced into said hollow element.

4. The connector assembly defined in claim 3, wherein a spacer member is provided for incorporation into the pivotal connection between said lever and said one pressure member, said spacer member being removable and replaceable with other different size spacer members for adapting the connector assembly to different size hollow elements.

5. The connector assembly defined in claim 3, wherein said one pressure member is a rigid body having angularly extending sections each of which has a pressure surface for slidably bearing on an internal surface of a hollow element, and upon each of which one of another pressure member is pivotally mounted to rock about a transverse axis.

6. The connector assembly defined in claim 5, wherein said sections are disposed at substantially right angles, for interconnecting two hollow elements in a substantially right angle comer.

7. The connector assembly defined in claim 5, wherein said sections are disposed to provide a starshaped member with the sections about 120 apart.

8. The connector assembly defined in claim 5, wherein said sections are disposed to form a cross having four apart rigid arms, and each arm is formed with a pressure surface for flush engagement with an internal surface of a hollow element, with the pressure surfaces of the arms that extend oppositely in the assembly being disposed in planes spaced a predetermined distance apart on opposite sides of a line corresponding to the central axis of hollow elements disposed thereon so that said hollow elements will be aligned with the center of the assembly when fitted onto said oppositely extending arms.

9., In the connector assembly defined in claim 3, said other pressure member being a lever that is substantially concave on the side that is to face said opposite internal surface of the hollow element and that is formed on the other side with a cylindrical transverse groove providing one element of said pivotal connection.

It). In a connector assembly according to claim 3, said resilient means being disposed between said first pressure member and said lever.

11. In a connector assembly according to claim 3, said resilient means being disposed between said lever and said opposite internal surface of said hollow element.

12. In a connector assembly according to claim 3, a resilient and compressible clamping member at the leading end of said lever with respect to the direction of introduction into said hollow element, said resilient and compressible clamping member providing both projecting means on said lever and said resilient means.

13. In a connector assembly defined in claim 3, resilient means being provided between said lever and the said lever is adapted to bear on the opposite'internal surface of said hollow element.

15. In a connector assembly defined in claim 3, said lever being a resilient beam that is deflected into energized condition during introduction of the assembly into said hollow element, and said deflected beam thereby serving as said resilient means in the assembly.

16. In a connector assembly defined in claim 3, the pivotal connection between said pressure members comprising a transverse cylindrical groove in one member within which is rockably fitted a transverse bead of corresponding shape secured on the other member.

I7. In a connector assembly defined in claim 3, said lever being a flexible beam having a concave side facing said opposite internal surface of the hollow element.

NITED STATES PATENT OFFICE E CERTIFICATE OF CQRRECTION M Patent No. 3 3 29 226 D e August 13, 1974 lnventofl Ulrich K reuse'l I It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below;

Column 9, 1ir 1e'15, after "ends" insert Column 10, lines 23 and 24 (lines 5 and 6 of claim 5) delete one of Signed and sealed this 14th day of January 1975.

(SEAL) Attest:

McCOI M. GIBSON'JR. c. MARSHALL DANN Attesting Officer Commissioner of Eatzents FORM powso (10459) uscoMM-Dc 60376-F'69 9 ".s. GOVERNMEMY PRIN'HIG OFF Cl 2 '99 0"35533 

1. A connector assembly for fixed attachment of a hollow element such as a tube to another element, said assembly consisting essentially of two pressure members rockably engaged intErmediate their ends, and adapted for axial introduction together into said hollow element, one of said members having a large area pressure surface formed for frictional engagement with one internal surface of said hollow element while the other of said members is adapted to engage an opposite internal surface of said hollow element, the other of said members being so constructed and arranged as to be energized solely by lateral pressure during said axial introduction into the hollow element between said internal surfaces for providing means resiliently oppositely biasing said members into engagement under pressure with the opposite internal surfaces of said hollow element, said one pressure member being a rigid body having a relatively large surface area for frictional engagement with said one internal surface of the hollow element, and said other pressure member comprising a lever separate from said body having intermediate its ends bearing surface means in rockable contact with bearing surface means on said one pressure member for rocking transversely of said hollow member, the effective axis of rocking being substantially normal to the direction of introduction of said assembly into the hollow element, said lever being adapted to bear at opposite ends only on said opposite internal surface of the hollow element.
 2. A connector assembly for fixed attachment of a hollow element such as a tube to another element, said assembly comprising two pressure members rockably engaged intermediate their ends and adapted for axial introduction together into said hollow element, one of said members having a pressure surface formed for slidable engagement with one internal surface of said hollow element while the other of said members is adapted to engage an opposite internal surface of said hollow member, the other of said members being so constructed and arranged as to be energized by lateral pressure during said axial introduction into the hollow element for providing means resiliently biasing said members into engagement under pressure with opposite internal surfaces of said hollow element, said one pressure member being a rigid body having a relatively large surface area for contact with said one internal surface of the hollow element, and said other pressure member comprising a lever separate from said body, means forming coacting engaged bearing surfaces on said lever and body providing for rocking of said lever relative to said body and transversely of each hollow member during introduction of said assembly into the hollow element, said lever being adapted to bear only at opposite ends on said opposite internal surface of the hollow element, and resilient means provided between said lever and the one pressure member substantially opposite the region where one end of said lever is adapted to bear on the opposite internal surface of said hollow element.
 3. A connector assembly for fixed attachment of a hollow element such as a tube to another element, said assembly comprising a first pressure member in the form of a rigid body having a relatively large surface area adapted to engage one internal surface of said hollow element, a second pressure member in the form of a lever separate from said body, bearing surface means on said lever intermediate its ends having coacting engagement with bearing surface means on said body providing said lever with a free pivotal connection with said first pressure member for rocking about an axis normal to the direction of introduction of said assembly into said hollow element, said lever being adapted to engage an opposite internal surface of said hollow member only at opposite ends, projecting means at said opposite ends of the lever adapted to positively engage said opposite internal surface of said hollow element, said rocking axis being disposed between said two pressure members at a first predetermined distance from said surface area of said first pressure member and at a second predetermined distance from a plane containing the surfacE of engagement between said projecting means of said lever and said opposite internal surface of said hollow element when the assembly has been fully introduced into said hollow element, and said surface area of said first pressure member and said plane being disposed at such predetermined distance from each other as to cooperate in pressing said surface area of said first pressure member against said one internal surface of said hollow element and said projecting means of said lever against said opposite internal surface of said hollow element when said assembly has been fully introduced into said hollow element, and said assembly comprising resilient means acting to urge said lever against said opposite internal surface of said hollow element when said assembly has been fully introduced into said hollow element.
 4. The connector assembly defined in claim 3, wherein a spacer member is provided for incorporation into the pivotal connection between said lever and said one pressure member, said spacer member being removable and replaceable with other different size spacer members for adapting the connector assembly to different size hollow elements.
 5. The connector assembly defined in claim 3, wherein said one pressure member is a rigid body having angularly extending sections each of which has a pressure surface for slidably bearing on an internal surface of a hollow element, and upon each of which one of another pressure member is pivotally mounted to rock about a transverse axis.
 6. The connector assembly defined in claim 5, wherein said sections are disposed at substantially right angles, for interconnecting two hollow elements in a substantially right angle corner.
 7. The connector assembly defined in claim 5, wherein said sections are disposed to provide a star-shaped member with the sections about 120* apart.
 8. The connector assembly defined in claim 5, wherein said sections are disposed to form a cross having four 90* apart rigid arms, and each arm is formed with a pressure surface for flush engagement with an internal surface of a hollow element, with the pressure surfaces of the arms that extend oppositely in the assembly being disposed in planes spaced a predetermined distance apart on opposite sides of a line corresponding to the central axis of hollow elements disposed thereon so that said hollow elements will be aligned with the center of the assembly when fitted onto said oppositely extending arms.
 9. In the connector assembly defined in claim 3, said other pressure member being a lever that is substantially concave on the side that is to face said opposite internal surface of the hollow element and that is formed on the other side with a cylindrical transverse groove providing one element of said pivotal connection.
 10. In a connector assembly according to claim 3, said resilient means being disposed between said first pressure member and said lever.
 11. In a connector assembly according to claim 3, said resilient means being disposed between said lever and said opposite internal surface of said hollow element.
 12. In a connector assembly according to claim 3, a resilient and compressible clamping member at the leading end of said lever with respect to the direction of introduction into said hollow element, said resilient and compressible clamping member providing both projecting means on said lever and said resilient means.
 13. In a connector assembly defined in claim 3, resilient means being provided between said lever and the one pressure member substantially opposite the region where one end of said lever is adapted to bear on the opposite internal surface of said hollow element.
 14. In a connector assembly defined in claim 3, resilient means comprising a compressible clamping member at the leading end of said lever, said compressible clamping member at the same time forming a projecting means of said lever, and a resilient member provided between said lever and the one pressure member substantially Opposite the region where the rear end of said lever is adapted to bear on the opposite internal surface of said hollow element.
 15. In a connector assembly defined in claim 3, said lever being a resilient beam that is deflected into energized condition during introduction of the assembly into said hollow element, and said deflected beam thereby serving as said resilient means in the assembly.
 16. In a connector assembly defined in claim 3, the pivotal connection between said pressure members comprising a transverse cylindrical groove in one member within which is rockably fitted a transverse bead of corresponding shape secured on the other member.
 17. In a connector assembly defined in claim 3, said lever being a flexible beam having a concave side facing said opposite internal surface of the hollow element. 